Dear forum,
I DL the trial version (still have 27 days) of Helicon 5.1.19 for Win XP and ran a few times both the stacking demo with the small JPGs of moth eggs on a leaf and with the great Remote utility driving my 7D shooting RAW.
Everything worked great for 2 days. This morning I wanted to show a friend and ran the demo and instead of gradually filling the bottom rectangle with the infocus pixels it just showed a uniformly colour rectangle for every shot and at the end produced a merged JPG which is totally BLACK !

I did not install anything. Tried to "Reset setting", rebooted the machine but nothing helped. Both the demo JPGS and my RAW stacks get composited into a large BLACK jpg !

Anything I can try please ? The remote shoots the stack just perfectly and on the filesystem I have the source RAW files which are absolutely normal.
Thank you for any help
Bob
PS I wanted to run a full demo with screenshots and maybe write an article for a photo magazine here in Italy. I hope it's ok with you of course giving all credits and directing to your website.